One explanation for the divergence in power between China and the Western powers is the invention of printing with movable type about 1440 in Germany. This made books cheap - both spreading new ideas rapidly and encouraging literacy in Europe. China, on the other hand, could not gain these important benefits. Their system of writing with thousands of characters did not lend itself to the low cost revolution of printing with movable type.

From:

http://en.wikipedia.org/wiki/Movable_type

Movable type has been credited as the single most important invention of the

The discovery and establishment of the printing of books with moveable type marks a

paradigm shift in the way information was transferred in Europe. The impact of printing is comparable to the development of language, and the invention of the alphabet, as far as its effects on the society.

Gutenberg's findings not only allowed a much broader audience to read

Martin Luther's German translation of the Bible, it also helped spread Luther's other writings, greatly accelerating the pace of Protestant Reformation. They also led to the establishment of a community of scientists (previously scientists were mostly isolated) who could easily communicate their discoveries, bringing on the scientific revolution. Also, although early texts were printed in Latin, books were soon produced in common European vernacular, leading to the decline of the Latin language. The first significant decline in illiteracy came with the Reformation, when translation of the Bible into the vernacular became widespread and Protestant converts were taught to read it.

In Korea and China, there were no texts similar to the

Bible which could guarantee a printer return on the high capital investment of a printing press, and so the primary form of printing was wood block printing which was more suited for short runs of texts for which the return was uncertain.

Some credit the printing press with giving Europe the technological and communication edge over Eastern countries in the end, one of the major questions in world history.

Map of world literacy

These UNESCO literacy estimates and projections are essentially based on literacy statistics collected during national population censuses and household surveys.